<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        console.log(NaN / 10);//NaN

        console.log(NaN == NaN);//false

        console.info("------------>")

        console.log(isNaN(NaN));//true
        console.log(isNaN(10));//false 10是一个数值
        console.log(isNaN("10"));//false "10"可以被转换为10
        console.log(isNaN("red"));//true
        console.log(isNaN(true));//false  true可以被转换为1
    </script>
</head>
<body>

</body>
</html>